Synchronous circuit make and break device



Nov. 2& 1939.

w. E. PALMER 2,181,283

SYNCHRONOUS CIRCUIT MAKE AND BREAK DEVICE Filed Sept. 10, 1937 4Sheets-Sheet 1 HIIIII Nov. 28, 1939. w. E. PALMER SYNCHRONOUS CIRCUITMAKE AND BREAK DEVICE 4 Sheets-Sheet 2 Filed Sept. 10, 1937 izaar zfir-Q Z JaZ 11,5- faher Nov; 28, 1939. w. E. PALMER SYNCHRONOUS CIRCUIT MAKEAND BREAK DEVICE 4 Sheets-Sheet 3 Filed Sept. 10, 1937 I IIIIIIIJ Nov.28, 1939. w. E. PALMER SYNCHRONOUS CIRCUIT MAKE AND BREAK DEVICE FiledSept. 10,- 1937 4 Sheets-Sheet 4 NON WW Patented Nov. 28, 1939 UNITEDSTATES PATENT OFFICE amass SYNCHRONOUS CIRCUIT: MAKE DEVICE Walter E.Palmer, Cicero, Ill. v Application September 10, 1937, Serial No.163,232 11-01mm. (01. 200-91) It is well known that in'maklng andbreaking an electric circuit, considerable arcing of the current isoccasioned at the make and break points which eventuallycausesconsiderable damage,

and is objectionable for many reasons. These arcings are occasioned'byreason of the fact that the making and breaking has heretofore beeneifected, especially in alternating current, when the current ispulsating or flowing, and the higher the voltage on the line the greaterwill be the are.

It is one of the objects of the present invention to provide an improvedmake and break device by means of the use of which an alternatingcircuit will be made and broken at the neutral point in the sine wave ofthe current, or when there is no current flowing, and to that end theinvention consists in providing an improved circuit make and breakdevice, embodying in its construction a motor operating in synchronismwith the current in the line which is to be controlled, whereby thecircuit will be made and broken when the.

current value is zero, or between alternations of this current.

To the attainment of these ends and the accomplishment of other new anduseful objects as will appear, the invention consists in the features ofnovelty in substantially the construction, combination and arrangementof the several parts hereinafter more fully described and claimed andshown in the accompanying drawings illustrating Figure 5 is a detailsectional view takenon line 55, Figure 3.

Figure 6 is a view partly in section as taken on line 66, Figure 3,showing in diagram the wiring.

Referring more particularly to the drawings, the numeral l0 designates ashaft which is journaled in suitable bearings suchas in supports ll heldin positionin any suitable manner. A drum l2 constructed of any suitableinsulating material and having contact plates l3-H recessed into theperiphery thereof, is mounted for free movement on the shaft l0.

Adjacent the end of the drum I2 is arranged a disc 16 having a cut awayportion I1 and a cut awayportion l8 to forni a shoulder l9. Encompassingthe shaft I0 is a coiled spring 20 one end of which rests against a lug21 on the disc I. and the other end of the spring'rests against aprojection 23, which is secured to the end of the drum l2 and isdisposed in the space or cut away portion ll of the disc IS. The disc I6is secured to the shaft ill by a set screw it.

Passing through the shoulder 19 is a screw 24 one end of which contactsthe support 23 so that 10 by adjusting the screw 24 a rotary adjustmentof the drum relative to the shaft l0 may be obtained.

If desired, .a lock nut 25 may be provided for locking the screw 24against adjustment.

Carried by a suitable support 26 are contact brushes 21 one for each ofthe contact plates l3l lon the drum l2 and are disposed to engage theperiphery of the drum l2 as well as the contact plates l4. These brushesmay be held in 20 position in any suitable manner but preferably bymeans of upright pins or members 28 which are preferably screw-threadedand are provided with nuts 29 to form binding posts to which onecontrolled is connected. If desired, one or more springs 3i may beprovided which tend to hold the brushes 21 in contact with, theperiphery of the drum. These springs contact the support 26 and also aninsulating 30 cross-bar member 32 which latter is adjustably secured inposition by means 01 bolts 33 as shown more clearly in Figures 1 and 4.

The'brushes 21 are preferably provided with 01'' balls 3!. A springpressed plunger 36 contacts I with one oi the rollers or ball: 25 and aconical member 31 contacts the other of the rollers or balls 35. Thisconical -member 31 preferably into the support 26 and held againstadjustment by means of a nut or collar 39. The upright 28'forming a partof the binding post preferably passes through a slot 40 so as to permitthe brushes 21 to be moved laterally for 45 a limited distance andwhenever individual adjustment is necessary or desired. The springpressed plunger 36 contacting the ball 35 tends to move the brush 21towards the right in Figure 4, and by adjusting the conical member 31upwardly the brush 21 will thus be moved to the right. However, when theadjustment to the left in Figure 4 is desired for the brush 21, theconical member 31is forced downwardly and the spring 55 of the terminals30 of the line which is to be 25 r forms an extension on a screw or bolt38 threaded inclined faces 34/ into which are (recessed rollers ,35

pressed plunger 35 will yield sufllciently to permit the brush to somove.

Another brush 4| similar to the brush 21 and similarly adjusted alsocontacts the periphery of the drum l2 and is in position to be engagedby the contact members l4 carried by the drum.

These members M are of such a length that they will span the spacebetween the brushes 21 and 4| when the drum is moving in the directionof the arrow in Figure 4 'at the points where the make and break of thecircuit is effected.

To the binding post 42 which is connected to the brush 4| is secured theother terminal 48 of the line or circuit which is to be controlled.

Thus it will be seen that when the drum I2 is rotated clockwise, thecontact members l4 will engage or move out of engagement with thebrushes 21-4| and thereby open or close the circuit in the controlledline.

The drum l2 by its rotation effects the make and break of the circuitand this drum is rotated intermittently by means of a synchronous motor44.

To that end there is provided on the shaft 45 of the motor 44 a gear 45of any suitable type, preferably a spiral gear which meshes with aspiral gear 41 that is mounted upon and rotates. freely about the shaftl8, and mounted upon the shaft l8 adjacent but spaced irom the gear 41is a disc 48, the disc being secured to the shaft for rotationtherewithin any suitable manner such as by means of a set screw 48.

Secured to and projecting laterally from the gear 41 and disposed in thespace between the gear 41 and the disc 48 is a collar which rotates withthe gear 41 and in a counter-clockwise direction as shown more clearlyin Figure 6. This collar 58 is provided with a shoulder 5| for a purposeto be set forth. Carried by the disc 48 is a dog 52 which is pivotallymounted thereto and intermediate its" ends as at 53, and is provided atone extremity with a shoulder 54. A second shoulder 55 is provided onthe dog 52 and this shoulder 55 is adapted to be moved into and out ofthe path of-the rotary movement of the shoulder 5| on the collar 58, soas to lock the disc 48 for rotation with the gear 41 and with it theshaft ID for rotating the drum l2. When the shoulder 55 is moved out ofengagement with the shoulder; 5| the disc tatior'i' by means of anotherdog 55, the operation of which latter will be presently described.

A spring 51 is provided formoving the dog 52 into an operative positionwith respect to the shoulder 5|. One end of this spring is anchored asat 58 to the dog 52 and at 58 to the disc 48. A stop pin'68 carried bythe disc 48 is provided for limiting the movement of the dog 52 aboutits pivot in a direction to cause the shoulder 55 to disengage or moveout of the path of rotation of the shoulder 5| on the collar 58.-

Thus it will be seen that when the dog 52 is in the position shown inFigure 6 the disc 48 will be held against rotation by the dog 55entering one of the notches or seats 5| in the periphery of the disc 48.In this position of the dog 52 the collar will rotate freely with thegear 41 but the drum l2 will remain still. When, however, the dog 52 ismoved into a position that it will contact the shoulder 5|, then thedisc 48 will be locked to the shaft H]- for rotation therewith, and asthe disc 48 lSjSBGLlI'BdtO the shaft iii of thedrum l2 for rotationtherewith, the drum will as correspondingly rotated and the contactpoints N 011th? necessary to control the adapted, when 48 will bearrested in its rodrum willbe moved into and out of engagement with therespective brushes 4 |-21.

Upon each operation of the dfsc the drum l2, they will move one-half ofa revolution, or 180, at which time the dog 52 will be shifted to causethe shoulder 55 to disengage the shoulder 5| and the end of the dog 58will drop into one of the notches or seats 5| in the periphery of thedisc 48 to hold the latter under tension and the end 54 of the dog '52against a stop shoulder 18 or 18 to be later described.

48 as well as- In order therefore to effect this operation it isoperation of the dog 52. In the present exemplification of thisinvention mechanism is shown for controlling the dog 52 to eflect amaking or closing of the circuit which is to be controlled, and alsomechanism is shown to effect the breaking of the circuit.

The control mechanisms, however, are arranged at different points in thecycle of operation of the dog.

The dog 55 is pivotally mounted as at 52 and a spring 53 one end ofwhich is anchored to the dog as at 54 and the other end being anchoredto a support 55 tends normally to move the end of the dog 55 in adirection to enter one of the seats 5| when the latter is in a positionto receive such an end.

An electroresponsive form of a magnet 55 and embodying a coil 51 hasco-operating therewith an armature 68 pivotally supported intermediateits ends as at 69, and is provided with a shoulder 18. This shoulder isthe armature 68 moves about its pivot in one direction to assume aposition in the path of movement of the shoulder 54 of the dog 52 whenthe disc 48 is rotated, and when the thoulder 54 contacts the shoulder10 the dog 52 will be rocked about its pivot 53 against the stress ofthe spring 51 so as to move the shoulder 55 out of engagement with theshoulder 5| and thereby release or unlock the disc 48 with respect tothe gear 41 so that although the gear 41 may be further rotated themovement of the disc 48 as well as the drum |2 will be arrested.

At this time the dog" 55 will enter the notch 6| in the disc 48., Theparts will remain in this position until the magnetic orelectroresponsive device is energized, to attract the armature 58 toswing it about its pivot 58 and thereby move the shoulder 18 out ofengagement with the shoulder 54 on the dog 52, allowing the latter underthe stress of the spring 51 to assume a position in the path of movementof the shoulder 5| on the collar {ratio again lock the disc 48 and thedrum |2 for rotation with the gear 41,

Arranged in proximity to the electroresponsive device 55 is anotherelectroresponsive device 1| embodying a coil 12. Co-operating with thiselectroresponsive device 12 is an armature 13 which is pivotallysupported intermediate its ends as at 14 and provided on one end of thearmature 13 is a shoulder or stop 15 with which a shoulder 15 on the endof the armature 68 is adapted to cooperate. A coiled spring 11 is.anchored by one end as at 18 to the end of the armature 68 and isanchored as at 19 to the end 88 of the armature 13.

The shoulder 15aat a predetermined time in the device, assumes a posi- 5of the shoulder 54 on the dog 52, with the result that the disc 48 andthe drum I2 will not be disturbed in their positions even though themagnet 66 were at that instant energized.

However, when the parts are in the position shown in full lines inFigure 6 the energization of the electroresponsive device 66 will causethe armature 68 to swing about its pivot to release the dog 52; thishappens when the coil 61 is dc-energized and the spring 11 moves thearmature 68 into the position shown in Figure 6.

Should the coil 12 be energized when the shoulder 10 of the armature 68is in engagement with the shoulder 54 of the dog 52, the shoulder 15 onthe armature 13 will'be moved into engagement with the shoulder 16 onthe armature 68 and lock the latter in such a position.

Thus it will be seen that when the coil 61 and the coil 12 are bothenergized, the dog 52 will not be released since the contactingshoulders 15 and 16 respectively of the armatures 13 and 68 will lockthe latter against movement. When the dog 56 is moved out of the notchor seat 6| a projecting portion 8I thereof will serve to close a makeand break device embodying spring arms 82 and 83 for a purpose to belater described.

The coil 84 together with a coil or electroresponsive device 85correspond respectively with the coil or electroresponsive device 61--12arranged on opposite sides of the mechanisms. The coils B1 12 co-operateto eflect what might be termed the off position while the coils 8485co-operate to efifect what might be termed the on position. 1

The synchronous motor 44 is provided with an inductive or startingwinding 86 and a syn- .chronous winding 81 and on the motor shaft,

and in the circuit of the inductive winding two centrifugal switches88-89 are provided.

The switch construction which controls the operation of the deviceembodies an intermediate spring member or finger 90 and spring members9I-92 on opposite sides of the member 90, and a switch button or knob 93being provided for the operation of this switch construction. It will benoted that upon the first depression of the button 93 electrical contactwill be made between the members 92 and 90 of the switch structure. Thisconnection, as will be later described, starts the motor into operationand locks both the on and oil release mechanisms. A further depressionof the button 93, and while the member 92 is in contact with the member90, will move the member 90 into electrical contact with the member 9Iand this will energize the respective electroresponsive devices.

.The motor operates in synchronism with the sine wave or pulsations inthe circuit, and one adjustment'may' be efiected by means of thestructure shown in Figure 5, that is, by means of the adjustment of thedisc l6-with respect to the drum, through the medium of the screw 24working through the shoulder I9 and against the support 23 carried bythe drum I2, the disc I6 being fast on the shaft by means of the screwI5, while a finer individual adjustment may be obtained by theadjustment of the conical elements .or members 31 operating upon thebrushes 21, shown more clearly in Figure 4.

r A centrifugal switch 89 operates to automatically cut out theinductive winding 86 from the line after synchronism of the motor withthe alternations or pulsations in obtained.

. The centrifugal switch 08 operates to cut out .coils 12 and 85 theline has been the local inductive circuit which would otherwise passthrough the' lock coils in series, to-wit: the coils 12 and 85 thatwould return to the inductive winding and which would complete asecondary circuit that wouldotherwise operate the lock coils 12-85contrary to the intention of the desired operation.

Obviously the breaker drum I2 may be geared to'obtain any desired degreeof ratio of rotation between the motor and the breaker drum.

When the motor is started by depressing the button 93, so as to form anelectrical connection between the members 92 and 90 of the manualcontrol switch, both the centrifugal switches or cut outs 88-89 areclosed, allowing the current to pass through both the inductive andsynchronous windings 86-81. These switches or cut outs 88-89 remainclosed until the motor has attained synchronism with the current sinewaves or alternations in the supply line of the controlling circuit. .Atthis time in the cycle .of operation of the device, both of the switchesor cut outs 8889 open, thereby cutting ofi current from the inductivewinding 86 and lock coils 1285, thus allowing the motor to run onthesynchronous winding only, and simultaneously de-energizing the lockcoils.

When the button 93 is depressed so as to move the member 92 intoelectrical the member 90 the current will flow as follows:

From line 94, to conductor. 95, contact 90, contact 92, conductor 96,conductor 9'5, at which point the current will divide, a portion thereofflowing through the switch 89, inductive winding 86, conductor 98,conductor 99 to the other side of the line I00, thus energizing theinductive winding 86 starting the motor. I

The other portion of the current will flow from the conductor 91 toconductor IOI, through synchronous winding 81 to the line I00, therebyenabling the synchronous winding to control the speed of the motor whensuch speed has been obtained.

After the current has passed through the switch 89, -a portion thereofwill flow through the conductor I05, to coil 12, conductor I04, coil 85,conductor I03, to switch 88, to conductor I02, conductor 99 back to theline I00. This circuit will continue to flow thereby locking the untilsuch time as the motor has attained synchronous speed, when switch 88automatically opens to cut off this last referredto circuit, therebyreleasing the locks 12 and 85.

Then the button 93 is further moved to cause the member 90 of the switchtoalso be moved into electrical contact with the member 9I of the.switch. flow from the line 94 through conductor 95, member 90, member9|, conductor I06, coil 61 out through conductor I01, conductor I08,back to the conductor I00 on the other side of the line, therebyactuating the oil release 61, provided motor has attained synchronousspeed, opening switch 88 and releasing lock 12.

The sequence of operations taking place upon the depression of the, offbutton 93 are as follows:

Upon bringing the contact members 92 and 90 into engagement the motor isstarted by the current .flowing through the inductive or startingwinding, and simultaneously the lock coils 12 In this position thecurrent willv and 85 are energized to lock the armatures 58 and magnet61 will be energized tending to pull the armature and shoulder 18 torelease the dog 52 to permit the latter to assume a position where itwill engage the rotating shoulder 5|; but this is prevented by thelocking shoulder 15 held by the energized locking magnet 12. However, assoon as the motor attains synchronous speed, the locking magnets arede-energized by the automatic opening of the centrifugal switches 8889,and the locking shoulder 15 is moved out of engagement with the shoulder16, thereby allowing the armature 68 to be attracted by the magnet 61 torelease the dog 52 into engagement with the rotating shoulder 5|, andthereby impart to the disc 48, and through it to the shaft in, a rotarymotion in the direction of the arrow shown in Figure 6.

dotted lines in Figure 4.

Upon the initial movement of the disc' 48, the dog 56 is raised from thenotch 6| of the disc 48, and thereby the switch members 82-83 arebrought into contact.

As soon as this takes place, the windings of the motor will bemaintained in line connection, even though the pressure from the ofl"button 93 is entirely removed, which would cause all of the members92--90--9| to move out of electrical contact; thus the function of theswitch 82-83 is to insure the completion of the cycles of operationinitiated by the depression of the ofi key 93.

The motion of the disc 48 continues for onehalf of a revolution, whenthe shoulder 54 will be engaged by the shoulder -A of the armature lever68-A, and the dog 52 will be disengaged from the rotating shoulder 5|.At this point the contact 56 will engage the second notch GI and therebylock the disc in its "off position and simultaneously separate theswitch arms 82-433, thus openingthe motor circuit.-

At the completion of these functions, the con-- tact member M will restopposite and out of en-. gagement with the brushes 21 and 4|, as shownin An examination of Figure 4 indicates that the break in the controlcircuit can only occur when the point BQon the contact l4 has reachedthe point B--| on the shoe 21. Otherwise a make, (that is, a completionof thecircuit) can only occur when the point "M" on the contact M hasreached the point M-| on the shoe 4|, upon a further rotation of thedrum l2 in the same direction, and after the insert M has once passedout of engagement with the shoes 21 and 4|. This involves a timeinterval between the'moment when the drum I2 is placed in motion and athe instant or instants when the current value is zero.

Another conductor ||I1-A leads from the coil 84 and is connected to theswitch member 8|-A- of the on button 9 3--A so that the coil 84 may beenergized when the button 83-A is depressed for the actuation of thearmature 68-A.

In this position of the parts of the switch and when the motor hasattained synchronism with the alternations in the line 94-46, the switch89 will automatically open, thereby cutting out the starting winding 86and this will de-energize the coil 12 with the result that the spring 11will move the armature 13 to the full line position shown in Figure 6.That is, so that the shoulder 15 will be moved to a pos'tion out ofengagement with the shoulder 16 on the armature 68. The coil 61 beingthen energized will attract the armature 68, moving the shoulder 10 outof contac Lwith the shoulder 54 on the dog 52, releasing the latter,allowing the spring 51 to swing the dog 52about its pivot so that theshoulder 55 will engage the shoulder 5| on the collar 50 and therebylock the disc 48 for rotation with the gear 41.

While the members 92, 90 and 9| of the switch are in electrical contact,current will also flow through the conductor 96, to the switch member83. As the disc 48 rotates, the dog 56 will be unseated from the notchor seat 6| causing the dog 56 to swing about its pivot 62 against thestress of the spring 63, with the result that the projecting portion 8|on the dog 56 will engage the contact arm 82 and close the switch, bymoving the member 82 into engagement with the member 83 so that.thecurrent flowing in through the conductor 96 and switch member-83 willthen continue to flow through the switch member 82,

conductor I08, back to the conductor 94 on the other side of the mainsupply line.

Thus it will be seen that by pressing the button 93 the motor will firstbe started on the inductive or starting winding 86, and the coil 12 willbe energized to move the armature 13 to a position that the armature 68will be locked against movement about its pivot 69, and the dog 52 willbe maintained in a position that the disc 48 will remain idle but themotor will continue to run.

When the motor has attained synchronism with the pulsations in the mainline, and upon a further depression of the button 93 so as to cause themembers 92, '90 and 9| to be all in electrical contact, current willfiow through coil 61 to energize it with the result that the armature 68will be attracted and the shoulder 10 will be moved out of engagementwith the shoulder 54 to release the dog 52 to cause the disc 48 to belocked with the gear. The disc will then rotate and the dog 56 will movethe contact members 82-43 into engagement, thereby closing the circuitcausing the motor to continue to run until the disc has assumed theposition that another one of the seats 6| will be positioned to receivethe dog 56. Just previous to this movement of the dog 56 the coil 61becomes deenergized, and the spring 11 will move the armature 68-A onthe opposite side of the line into a position that the shoulder 54 ofthe dog 52 will engage a shoulder 1IJ- -A on the armature 68-A, so thatthe'dog 52 will be shifted to release the disc 48 with respect to thegear 41. .Just at this time one of the seats or recesses 6| will be'in aposition to receive the v dog 56.

It is of course to be understood that to perform the opposite operation,that is, what might be termed the on position, the other button 93-Awhich controls the coils 84 and 85 must be operated, when the samesequence culminating in the operation of the ing coil.

The coils 61-84 are respectively locked by the on actuatcoils 12 and 85until the motor attains synchroof events occur,"

' be termed the on or switch.

ensues -82-'83 is provided for the purpose of maintaining the motor inoperation until the full throw of the drum [2 has occurred, regardlessof whether either of theswltch buttons 83-A is closed or open.

Obviously the device may be geared for the desired ratio of rotationbetween the motor 44' and the drum I2.

It is thought that the operation will be clearly understood from theforegoing, but briefly stated, it is as follows:

In Figure 4 the circuit breaker is shown in what might be termed aclosed position, and the operation of the device will be described inconnection with the left hand portion of the wiring diagram shown inFigure Gembodying the-coils 61 and I2.

To open the controlled switch, the left hand button 83 is depresseduntil the member 82 comes into contact with the intermediate member 88.This allows the current to flow from the controlling circuit through themotor winding and the coils 1284 in parallel back to the other side ofthe line.

'The motor starts on'the inductive or starting winding 88, and whensynchronous speed has been obtained, the coils 12-85 are de-energizedthrough the opening of the centrifugal switches 88-88, .thus allowingthe actuating mechanism to operate, which occurs upon the movement ofthe intermediate member 80 of the switch into electrical 'contact withthe'member M of @the It-will be seen that the member 8| of the switch isconnected with the coils 81, which latter when energized attracts thearmature 88, allowing the shoulder 55 on the dog 52 to engage theshoulder 5| on the collar 80. The collar 58 then turns with therevolution of the motor 44, being fastened to the gear 41 for rotationtherewith and which gear 41 is on the motor-shaft. Thus when theshoulder 55 of the dog 52 engages the shoulder 5i on the collar 50, thedog 52 together with the disc '48 on which it is mounted is revolved ina counter-clockwise direction for one-half turn until the shoulder 54 onthe dog 52 engages the shoulder Hi-A on the armature.

88A that is controlled by the coil 84, as shown in Figure 6. Theengagement of the shoulder 54 with the shoulder HJA will swing the dog52 about its pivot 53 against the stress of the spring 5-! to cause theshoulder 55 to move out of engagement with the shoulder ll on the collar88.

In either position, that is, whether the circuit make and-break deviceon position, the dog 88 will engage in one of the seats or recesses IIin the'disc 48 for the purpose of holding thedrum in such position. Thedog 58 also acts to hold the points 54 and 10, or 54 and '|0A accordingto the position of the disc 48, under tension, that is, the end of thedog 52 will be held firmly against the stop 10 or ID-A. The tension ofthe spring 83 is preferably greater than the tension of the spring- 51,for the reason that the spring 51 would otherwise overcome the tensionof spring 88 and tend to rotate the dog 82 about its pivot 53; whichaction would force the disc 48 to rotate in a. counter-clockwisedirection, which is not desired. Such counter-clockwise rotation wouldresult in the spring 81 drawing or positioning the dog I! so that theshoulder 88 would comis at rest in what might" tact II, and therebycause another rotation fol the disc 48 in a clockwise direction, whichis not desirable at that particular time in i the cycle of operation ofthe disc.

cycle of opera- 5 and all of the coils Upon completion of the OH tion,the drum 1! will stop will become de-energized.

To perform the opposite operation from that which is, performed by thestructure shown on the left hand side of Figure 6, and to employ the 10coils 84-85, all that is necessary is to depress the other button 83-Aor what might be termed the on button, when the same sequence of eventsoccurs, as with the operation of the button 93, culminating in the oration or activity of the 15 coils 84-85. v

If desired, a suitable closure or cover i119 may be provided for theentire mechanism, and \this cover maybe held in position or supported inany desired or suitable manner.

While the preferred form of the invention has been herein shown anddescribed, it is to be understood that various changes may be made inthe details of construction, and in the combination and arrangement ofthe various parts, within the scope of the claims, without departingfrom the spirit or this invention.

What is claimed as new is:

1. A rotary circuit make and break device, a synchronous motor connectedwith an alternating current circuit and from which motor said make andbreak device is normally disconnected, means embodying a shlftableconnecting element for connecting said make and break device with themotor for rotation therewith, means operating automatically to shiftsaid element to lock the make and break device and the moimr foroperation in unison in a manner thatat the instant of the make or breakthe current value is zero, means also operating automatically, and at 4a different point in the. cycle of rotation of the make and breakdevice, to shift said element to unlock the make and break device fromthe motor, and means operating to maintain the motor in operation untilthe full throw of the make and break device has occurred. g

2. A rotary circuit make and break device, asynchronous motor connectedwith an alternating current circuit ,nd from which motor said make andbreak device is normally disconnected, means embodying a shiftableconnecting element for connecting said make and break device with themotonmeans operating automatically to shift said element to lock themake and break device and'the motor for operation in unison in a mannerthat at the instant of the make or break the current value is zero,means also operating automatically, and at a different point in thecycle of rotation of the make and break device,

to shift said element to unlock the make and break device from themotor, and means operating to maintain the motor in operation until thefull throw of the make and break device has oc-- curred, the lastrecited means embodyinga supplemental circuit make and break device,responsive in its operation to the operation of a por-' tion of. theconnecting means between the motor and the first recited make and breakdevice.

3. A rotary make and break device, a motor connected to an alternatingcurrent and nor- 70 mally disconnected from said make and break device,connecting means for connecting the motor and make and break device foroperation in electroresponsive means for rendering the means forrendering the said connecting means inactive, means for controllingtheoperation of the electroresponsive means, means operating automaticallyto cut out the starting winding of the motor when the motor operates insynchronism with the alternating current wave, and means operatingautomatically to interrupt any local circuit which might be establishedthrough and between said electroresponsive means and troresponsivedevices for causing said pivotally mounted element to become active in amanner that at the instant of the make or break the current value insaid circuit is zero, and means whereby said electroresponsive devicesmay be controlled.

5. In combination, a rotary electric circuit make and break device, asynchronous motor connected to an alternating current circuit and fromwhich motor said make and'break device is normally disconnected, ashouldered element connected with the motor for rotation therewith, anintermittently rotatable element connected with the make and breakdevice, a pivotally mounted element carried by said rotatable elementand movable into and out of active engagement with said shoulderedelement to lock said make and break device for rotation with saidrotatable ele-- ment, electroresponsive devices for causing'said''pivotally mounted element to become active in a manner that at theinstant of the make or break the current value in said circuit is zero,and electroresponsive devices for causing the said pivotally mountedelement to become inactive.

6. A rotary electric circuit make and break device, a synchronous motorconnected to an alternating current circuit and from which motor saidmake and break device is normally disconnected, a shouldered elementconnected with the motor for rotation therewith, an intermittentlyrotatable element connected with the make and break-device, a pivotallymounted element calried by said rotatable element and movable into andout of active engagement with said shouldered element to lock said makeand break device for rotation with said rotatable element,electroresponsive. devices for causing said pivotally mounted element tobecome active in a manner that at the instant .of the make or break thecurrent value in said circuit is zero, means whereby saidelectroresponsive devices may be controlled, and means for arrestingsaid rotatable element against overthrow when the said piv- ,otallymounted element is rendered inactive.-

7. A rotary electric circuit make and .break device, a synchronous motorconnected to an alternating current circuit and from which motor saidmake and break device is normally disconnected, a shouldered elementconnected with the motor for rotation therewith, an intermittentlyrotatable element connected with the make and break device, a pivotallymounted element car ried by said rotatable element and movable into .thecontact will move out and out of active engagement with said shoulderedelement to lock said make and break device ior rotation with saidrotatable element, electroresponsive devices for causing said pivotallymounted element to become active in a manner that. at the instant of themake or break the current value in said circuit is zero, means operableat will for-rendering the electroresponsive devices active and inactive,means for arresting the said rotatable element against overthrow whensaid pivotally mounted element is rendered inactive, and means wherebythe said arresting,

means will operate at .a predetermined time in the cycle ofoperation ofsaid rotatable element, to maintain the motor in operation until a fullthrow 0! the make and break device has occurred.

8. In a make and break device, a synchronous motor, connected to analternating current circuit, a-rotatable contact carrying elementnormally disconnected from said motor, a rotatable dog carrying elementconnected with said contact carrying element for rotation therewith,means connected with the motor and with which means the dog co-operatesto lock said element for rotation with the motor, electroresponsivedevices, armatures individual to the electroresponsive devices andcontrolled thereby, means carried by the armatures to be moved intointerlocking relation whereby one armature will be locked againstoperation, the last said means also adapted to be moved out ofinterlocking relation topermit one of the armatures to be engaged bysaid dog to move the latter out of the position in which it would lookthe contact carrying element for rotation with the motor, and meanswhereby said armatures will be actuatedto render said dog active andinactive in a manner that at the instant of the make or break the valueof the current. in the line is zero. 7

9. A device of the character described embodying a synchronousmotor-connected to an alternating current, a rotatable member separatefrom the motor, a contact carried by said memher, a, pair of brushesco-operating with said contact, said brushes spaced from each other inthe direction of rotation of said contact and for a distance less thanthe length of said contact,

and means operating automatically to connect said member with the motor,in a manner that of engagement with one of the brushes to break thecircuit, and into engagement with the-other brush to make the circuit atthe instant or instants when the current value is zero.

10. A rotatable electric circuit make and break device for controllingthe circuit of a synchronous motor connected to an alternating currentcircuit, said device embodying a shouldered element connected with themotor for rotation therewith, an intermittently rotatable elementconnected with the make and break device, a locking element mounted uponand movable with and with respect to the last said element,electroresponsive means for shifting said locking element with respectto its support and into en'- ga'gement with said shouldered element in amannet that at the instant of the make and break the current value willbe zero, and electroresponsive means for moving said locking element outof active relation with respect to said shouldered element.

11. A- rotatable electric circuit make and break,

device for controlling the circuit of a synchronous motor connected toan alternating current cir cult, said device embodying a shoulderedelement means for connected with the motor for rotation'therewith, anintermittently rotatable element connected with the make and breakdevice, a locking elemmtmoun d upon and movable with and with respect tothe last said element. eleotroresponsive said locking. element withrespect to its support and into engagement with said shouldered elementin a manner that at the instantotthemakeandbreakthecurrent value 10 willbe m, electroreeponsive means for moving 7. said locking element out ofactive relation with respect to said shouldered element, and means formaintaining the motor in operation until a full throw of the make andbreak device has occurred, the last recited means embodying asupplemental circuit make and break device rendered activeby theengagement therewith of the said locking element when the latter isshifted out of engagement with said shouldered element.

WALTER E. PALMER.

